package com.wangchao523.util.servletUtil;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class ImageServlet extends HttpServlet {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private static final String CONTENT_TYPE = "text/html; charset=GBK";

	// Initialize global variables
	public void init() throws ServletException {
		// PropertiesUtil.createInstance();
	}

	// Process the HTTP Get request
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		HttpSession session = request.getSession(true); // 获取会话
		ServletOutputStream output = response.getOutputStream();
		int width = 60;
		int height = 20;
		BufferedImage image = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB);
		Graphics g = image.getGraphics();
		Random random = new Random();
		g.setColor(getRanColor(200, 250));
		g.fillRect(0, 0, width, height);
		g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
		g.setColor(getRanColor(160, 200));

		for (int i = 0; i < 155; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			g.drawLine(x, y, x + xl, y + yl);
		}
		String sRand = "";
		for (int i = 0; i < 4; i++) {
			String rand = String.valueOf(random.nextInt(10));
			sRand += rand;
			g.setColor(new Color(20 + random.nextInt(110), 40 + random
					.nextInt(110), 60 + random.nextInt(110)));
			g.drawString(rand, 13 * i + 6, 16);
		}
		session.setAttribute("CHKNUM", sRand);
		g.dispose();
		ServletOutputStream sos = response.getOutputStream();
		ImageIO.write(image, "JPEG", sos);
		sos.close();
		output.flush(); output.close();
	}

	Color getRanColor(int fc, int bc) {
		Random random = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

	// Process the HTTP Post request
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}

	// Clean up resources
	public void destroy() {
	}
}